Setting X0 and Y0 with 1/2" 3-fluted End Mill

[AZRoger]

This may be close to some other post - search ignores X0 and Y0 so it's hard to narrow it down.
As the title suggests, I'm having no luck getting repeatable settings for X0 and Y0 directly for this three fluted end mill.
What I have resorted to is using an 1/8" v-bit tool (with its collet) to set X0 and Y0.
Then I remove the v-bit and put the 1/2" end mill (with its collet) to set Z0.
It seems to work but I'm wondering if there's a better way. Thanks.
Roger

[WoodEraser]

Roger,
I use the V-Bit also to set x & Y zero then put in what ever bit I'm going to use and use touch plate to set Z0.
Because machine returns to XYZ0 at end of cut you only need to set Z when you change bits.
If I'm going to continue on project tomorrow I will change to bit I'll be using then set Z) then park the bit at XYZ0.
Hope this helps.

[AZRoger]

I've been leaving the machine on 24x7 to avoid having to recalibrate things.
Parking it over night at XYZ0 is a much better solution. Thanks.
Roger

[milo30]

If you are doing repeated cuts on the same size material, you can make a small jig so everytime you replace the material it will be in the exact same spot and then a jig for that particular bit that will ensure it all lines up. Here is a good video showing one way. http://www.youtube.com/watch?v=GJ0m6OKHiQc

Parking it overnight is easiest but if you want to go back to it at another time the video shows a good way of doing it,..

[BillK]

I made my Scarf board into a tooling plate. http://www.cncsharktalk.com/viewtopic.php?f=2&t=2471 Pins locate the X and Y axis, zero is always in the same place for X and Y unless I move it. Z zero is the only reset.

If I do have to set a new XY zero, I use a 60 degree V bit and the step function to get it as close as possible.

[AZRoger]

If you are doing repeated cuts on the same size material, you can make a small jig so everytime you replace the material it will be in the exact same spot and then a jig for that particular bit that will ensure it all lines up. Here is a good video showing one way. http://www.youtube.com/watch?v=GJ0m6OKHiQc
Parking it overnight is easiest but if you want to go back to it at another time the video shows a good way of doing it,..

I do have a fixture bolted to the table and it was machined in place to receive the work pieces. Repeatable part placement isn't a problem.
I like the idea shown in the video. It would work fine for me. I'd like to use a reference point on the fixture rather than on the part.
In the video, he has a 0,-125 reference hole. He entered the -125 into his control software. With the CNC Shark Control Panel I have (ver. 1.5.0.23i) I can only Zero out the X, Y and Z coordinates. I can't set them to a value I get to key in. So maybe there's another way.

There's an option in the material setup box with Vectric V-Carve and Aspire that let's you specify offsets from any of the corners or the center. Is this where I'd put in Y 125? Or would it be Y -125? How do I know? There's no mention of the "Use Offset" option of the material setup box in the Aspire manual. 345 pages and not a word. The toolpath preview always looks the same whether I use the offset or not. Does it just effect the .tap file? Has anyone tried it?

Roger

[milo30]

I haven't tried any of that so I can't answer but what I do is similar to the video. I normally work off the center rather than corner so I just have a board with hole made in center with the appropriate bit. I can then line it up pretty easily if I lose my zero.

I really want to pick up a laser for it eventually

[milo30]

I finally got some time off work so I went in to take a look at offset that you are speaking of on the material setup box. Basically it looks like that is where it will start cutting your project relative to your set XY 0. If you zero your machine on the corner, and use that location in vcarve or aspire, and tell it to run the file, it will work off that as your 0.0 as you would expect.

If you zeroed the machine to the same corner, told vcarve to use the corner as your 0.0, but checked the use offset box, then say tell it to use X.0 and Y. 10, even though your bit is sitting on 0.0, when you hit run it will make the real 0.0, 0.10. If you check the box and add a high enough number in vcarve, then preview toolpaths you will see what it does. I don't know why you would want to use this instead of just aligning your machine to the desired start point and make that 0.0. Maybe it is to give you a place to set your Z for bit changes where the material would have been cut away from a previous bit.

I had actually never noticed it being there before BUT, I found that I had it checked and may have found the solution to a problem that I have been having.

[gordread]

I do have a fixture bolted to the table and it was machined in place to receive the work pieces. Repeatable part placement isn't a problem.
I like the idea shown in the video. It would work fine for me. I'd like to use a reference point on the fixture rather than on the part.
In the video, he has a 0,-125 reference hole. He entered the -125 into his control software. With the CNC Shark Control Panel I have (ver. 1.5.0.23i) I can only Zero out the X, Y and Z coordinates. I can't set them to a value I get to key in. So maybe there's another way.

Have you tried playing with the 'set' function in the Shark Controller? I use it all the time for setting my z height. I use an aluminum block that was machined to exactly 1.000 inches and use that as a manual 'touch plate'. Once my bit touches the block I change the z in the set function to 1.000 and it is perfect, with no guessing.

I think that you could do something similar, and position your bit into the hole, and then use the set function to change the x to '0' and the y to '-0.125'. Then when you hit the 'Move to 0,0,0' it will lift out of the hole and move to the corner.

Gordon

[AZRoger]

Have you tried playing with the 'set' function in the Shark Controller? I use it all the time for setting my z height. I use an aluminum block that was machined to exactly 1.000 inches and use that as a manual 'touch plate'. Once my bit touches the block I change the z in the set function to 1.000 and it is perfect, with no guessing.

I think that you could do something similar, and position your bit into the hole, and then use the set function to change the x to '0' and the y to '-0.125'. Then when you hit the 'Move to 0,0,0' it will lift out of the hole and move to the corner.

Gordon

Gordon,
The SET function does exactly what I need to do. The "hover text" for the button says "Clear X0". So I didn't give it a try. I guess I shouldn't believe everything I see!

... I don't know why you would want to use this instead of just aligning your machine to the desired start point and make that 0.0. Maybe it is to give you a place to set your Z for bit changes where the material would have been cut away from a previous bit.

Milo,
My problem is with X and Y. I can't actually see where the center of the cut will be with the 1/2 inch three fluted end mill. No matter how I turn the bit there's no symmetric view that let's me see the center of the cut or both outer extremes at the same time. I'm trying to avoid a tool change just to get my X0 and Y0 back.

If I drive the tool into a pre drilled 1/2 inch hole in the fixture I can then SET X and Y appropriately as suggested by Gordon. In my case the numbers would be something like X=25mm, Y =-10mm. Your experiments suggest that I could let the hole in the fixture be X0, Y0 and use the offsets in the material setup to put the toolpath at the right place.

Gordon and Milo,
I think the tie breaker here is based on a built-in "feature" of the Shark. It always goes to 0,0,0 at the beginning of a "Run file", then continues with the real toolpath.
I think I prefer to have that location actually on/over the work piece. That's my chance to hit E-Stop before bad things happen. So for now, I'm using offsets of 0 in the material and I'll adjust X and Y as part of the machine setup.

Thanks to both of you.

Roger